The instant invention relates to liquid or semi-liquid, i.e. fluid, bleach-containing, abrasive scouring cleansers. Solutions of liquid hypochlorite and surfactant are thickened by means of a colloid-forming clay material to form a false body composition capable of suspending conventional scouring abrasives. Physical and chemical stability of such formulations is realized by employing a buffering agent capable of maintaining the false body compositions at a pH of from about 10.5 to 14.
There has been an increasing demand for bleach-containing liquid detergent compositions adapted for cleaning hard surfaces. To obtain optimum cleaning and consumer acceptance, such compositions must be homogeneous and easily pourable. These compositions, when intended for the retail consumer market, should maintain their homogeneity and bleaching effectiveness during ordinary periods of storage and use.
An extremely difficult problem in providing hard surface bleaching detergent compositions of this type is maintaining insoluble abrasive particulate material uniformly dispersed throughout while at the same time formulating compositions which contain bleaching and surfactant materials that are normally highly chemically active. The chemically active materials of such compositions tend to degrade and render ineffective those other composition materials which are designed to maintain abrasive suspension or provide more desirable composition physical properties. Some agents designed to aid in abrasive suspension also tend to deposit on the hard surfaces being cleaned, thereby leaving an unsightly film or haze.
Another problem involving liquid or semi-liquid compositions containing strong bleaching agents and surfactants relates to the chemical stability of such products. In addition to rendering some suspending agents ineffective, chemical interaction of bleach and surfactant materials with such other ingredients as well as with each other can result in the degradation and loss of effectiveness of the bleaching agents and surfactants themselves.
Finally, liquid scouring compositions are inherently difficult to utilize effectively on hard surfaces positioned in such a way that free-flowing liquids quickly run along such surfaces, thereby minimizing cleanser-surface contact time. This is especially noticeable when vertical surfaces such as walls are to be cleaned.
Some liquid, bleach-containing abrasive hard surface cleaning compositions are known to the prior art. For example, U.S. Pat. No. 3,630,922 describes liquid, abrasive-containing, bleach-containing detergent compositions capable of suspending particulate abrasive material homogeneously throughout the composition. Such a composition, however, requires the presence of particular types of surfactants and electrolytes and is generally of such low viscosity that relatively large amounts of this material are required to insure that enough scouring composition remains in contact with hard surfaces during a scouring operation. U.S. Pat. No. 3,558,496 describes a thickened bleach composition capable of remaining in contact with hard surfaces for extended periods of time. Such a composition, however, contains no surfactant or abrasive material and further requires a rather particular mixture of positively and negatively charged clay thickening agents in order to realize acceptable thickened bleach products.
Thus, there is a continuing need for hard surface scouring products which are chemically and physically stable, which are capable of remaining in contact for extended periods of time with the hard surfaces to be cleaned and which are highly effective in removing soil and stain from such hard surfaces by virtue of the presence of highly chemically active bleaching and surface active agents as well as insoluble abrasive materials.
Accordingly, it is an object of the present invention to provide bleach-containing, surfactant-containing abrasive hard surface scouring compositions which are physically stable, i.e., compositions which are capable of maintaining abrasive particulate material uniformly suspended throughout and which do not excessively separate into discrete physical phases.
It is a further object of the present invention to provide such scouring compositions which are chemically stable over extended periods of time in spite of the presence of materials which are normally highly chemically reactive.
It is a further object of the present invention to provide such scouring compositions which are capable of remaining in contact with hard surfaces for an extended period of time.
It is a further object of the present invention to provide such scouring compositions which are highly effective in removing stain and soil from hard surfaces without themselves depositing an unsightly film or haze onto such surfaces.
It has been surprisingly discovered that by combining particular hypochlorite-yielding bleaching agents, particular bleach-stable surfactants, and certain buffering agents in an aqueous solution thickened with a certain type of colloid-forming clay and abrasive material, stable false body compositions can be obtained which accomplish the above objectives and which are surprisingly superior to hard surface scouring compositions of the prior art.